Probiotics are most widely recognized for their ability to boost immune function, aid digestion, keep harmful microorganisms in check and aid in nutrient absorption. But newer research indicates that probiotics, delivered via fermented dairy foods, also might be a useful tool for weight management, blood sugar control, bone and cardiovascular health promotion, and more.
Obesity is one of the biggest health challenges in America, and many of us are still struggling in February to work off extra pounds from our holiday indulgences. Recent studies link both probiotics and yogurt consumption to weight reduction.
In a 2018 review of 15 studies covering 957 subjects, administration of probiotics resulted in a significantly larger reduction in body weight and fat percentage than a placebo (https://tinyurl.com/ssau8jr). The authors noted that the effect sizes were small, but study durations were only three to 12 weeks.
A much larger and longer study of 120,877 U.S. men and women examined the effect of intake of individual foods on weight gain over 24 years (https://tinyurl.com/svq2tek). While intake of potato chips and fries, processed meats and sugar-sweetened beverages was associated with significant weight gain, consumption of one serving of yogurt per day was associated with an average weight loss of 0.82 pound per year.
This study did not specify if the yogurt contained probiotics; however, some consider the standard yogurt cultures Lactobacillus bulgaricus and Streptococcus thermophilus to be probiotic, as they confer the health benefit of enhancing lactose tolerance. The study’s author, American cardiologist and epidemiologist Dariush Mozaffarian, did note that when sweetened yogurt and plain yogurt were compared, “each was associated with relative weight loss, although when sweetened, about half the benefit was lost.”
Controlling blood glucose
Another major health issue in the United States is type 2 diabetes (T2DM). Two separate systematic reviews show benefits of probiotics in this area.
A 2016 meta-analysis of five studies examined the effects of probiotics on blood glucose in individuals with T2DM. The authors found that when compared to a placebo, fasting blood glucose was significantly lower with probiotic consumption (https://tinyurl.com/v6u6a4v).
A separate 2015 meta-analysis of 17 studies revealed that probiotic consumption, compared to a placebo, significantly reduced fasting glucose, fasting plasma insulin and insulin resistance (https://tinyurl.com/slnbpph).
Osteoporosis and resulting risk of bone fracture are major concerns for postmenopausal women. A 2019 Canadian meta-analysis compared two fermented milk products — yogurt and cheese — and their influence on bone health.
In a meta-analysis of three cohort studies involving 102,819 women, higher yogurt consumption was associated with reduced hip fracture risk (https://tinyurl.com/ql45xn7).
Published in 2019, an Australian study followed women aged 45-50 years at baseline in 2001 through five surveys until 2016. The results revealed that a high intake of yogurt and total fermented dairy was associated with lower cardiovascular disease risk than observed in the lowest tertile of dairy product intake (https://tinyurl.com/womer9m).
Although not as serious as some of the other health issues, flu-like respiratory tract infections (RTIs) are annoying, often result in unnecessary medical prescriptions, and take a toll on worker productivity. A study published in 2019 revealed that two meta-analyses reported the efficacy of probiotics in reducing the incidence and duration of RTIs, number of antibiotic courses and days absent from work (https://tinyurl.com/wlnvuqj).
Yogurt and kefir are the most common food sources of probiotics. As Mozaffarian notes, we too often look to isolated nutrients for health benefits. However fermented dairy foods offer high-quality protein, essential vitamins and minerals, and probiotics that can enhance health on multiple fronts.